Flat roofing in Stourpaine

Lean tos, garages and the small flats on old cottages. Village flat roofs are seldom the main roof. They are a kitchen or bathroom built onto the back, a garage or cart store, a porch, a bin store, and sometimes a little lead flat capping a bay or a stair window. The coverings we meet are torch on felt, built up felt in three layers finished with a mineral cap, GRP fibreglass and the occasional old lead. Before pricing we strip a section, because the deck settles the argument. Plywood or OSB that has stayed dry can be re-covered straight away. Chipboard decking that has drawn water sags between the joists and comes off, with new boards fixed down first. After that it is EPDM rubber in a single sheet, fibreglass, a new torch on system, or single ply on anything long and open.

Standing water, falls and outlets. Ponding is not a cosmetic complaint. Water that sits works into every lap and seam and the first sharp frost opens them up. It is almost always a fall that was never laid, firrings cut too shallow, tapered insulation crushed, or a rainwater outlet packed with leaf litter and grit. We put the falls back so the roof drains at an outlet rather than in the middle, to the minimum BS 6229:2025 on flat roofs sets, and then check the gutter, hopper and downpipe below can actually carry it.

The details that let water in. It is the edge trim, the drip, the apron where the roof meets a wall, the kerb round an opening and the laps. On felt you get a blister, a bubble or a split. On single ply it is a lifted or failed seam. On fibreglass it is a crack at a sharp internal angle where the deck flexes. Soft material is taken out first. The upstand is then built to a proper height and tucked behind the covering, and the laps are welded or bonded so nothing depends on sealant.

Openings, abutments and the build up underneath. A rooflight, a lantern, a Velux, an access hatch or a soil and vent pipe wants a kerb and a collar. Where a flat roof meets brick, flint or stone we chase in a cover flashing in lead, cut so it moves with the weather instead of tearing. On a parapet we look at the coping and whether a cavity tray sits behind it. Older roofs here are cold roofs, insulation between the joists with a dead void above, which is where condensation collects and interstitial damp rots the deck out of sight. Warm roof construction fixes it. Insulation board goes above the deck, the vapour control layer goes below the board, and the dew point lands in the PIR rather than on your joists.

No rate per square metre, because the square metres are the easy part and what is under the covering is what decides the job.

Getting to it. A garage on a shared yard, a kitchen lean to against an old flint wall, and a small flat over a bay window are three different jobs before anything is lifted. A garage or a single storey extension will often come off a tower, anything above a two storey wall wants a scaffold, and the platform has to stand while the deck is open rather than for an afternoon. The work at height rules are why it is a priced line rather than something folded into a rate.

The deck under the covering. A sound deck can be re-covered. Chipboard that has been wet for years, or ply that gives underfoot, has to come off and be replaced, and you cannot tell which you have from the ground or from a photograph. We lift a corner before quoting, because the deck is the single biggest swing in the price.

The falls, and where the water is meant to go. Most flat roofs that fail were never laid to a fall, or the fall runs at an outlet that has since been blocked or built over. Correcting it with firrings is more work than laying a membrane and it is the difference between a roof that lasts and one that ponds. Upstands, edge trims and each outlet are priced one at a time, because that is where the hours and the leaks both are.

Comparing quotes? Ask which system is being quoted and how many layers, whether the deck is being renewed or covered over, whether the falls are being corrected with firrings, how the upstands, outlets and edge trims are detailed, and whether the scaffold and the skip are in the price. Two quotes for the same job are usually two different jobs.

Stourpaine has a conservation area over its older core, and the thing to understand is what it does and does not control. It does not control how a flat roof is built. You can have a warm roof, new firrings, PIR above the deck and a modern membrane without anybody objecting, because none of that is visible. What it controls is appearance where the roof can be seen.

In practice that means two questions. Is your roof actually visible from a road, a lane or the footpath, or is it hidden at the back behind the ridge. And are you changing what it looks like, or putting back what was there. Like for like is maintenance. A run of new rooflights, a lantern, a raised parapet or a bright silver trim where there used to be a dark edge is a change of appearance and it is worth a short call to Dorset Council first. If the house itself is listed, listed building consent is a separate matter again, and it can apply even to repair work.

We cover Stourpaine, Durweston, Pimperne and the villages up the Stour valley, along with the rest of DT11, and the site visit and quote are both free. You are dealing with Bournemouth Roofing & Building, the trading name of Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719, which you can look up in a minute. Thomas Hannen's business, and he is the one who comes out to price the job, not a salesman. A verified customer's 10 out of 10 on Checkatrade. The visit and the written quote are both free.